Instances of Read tends to expect the format that Show would output. In
the case of lists, it's [elem1,elem2,elem3].

You can either modify your exporter to output values in the format that
read expects, or you could use a combination of the functions 'lines',
'words' and 'read' to split the input into a list of lines, split each
line into a list of words, and finally use read to go from word to
Double.